For this one I used these tools:Spore (Making the creature)Darkspore (For the eye)Dark Injection V5 (A mod which "injects" the Darkspore parts in Spore)Blender (Editing and exporting to .SMD)Paint .NET (Textures to .VTF)Notepad ++ (Editing .VMTs)GUIStudioMDL (Compiling)This was my attempt at the Space Core from Portal 2.

This download looks like an addon. You need to extract the downloaded zip and put the addon folder in your Garry's Mod addons folder. You should end up with a directory structure similar to below: